Micropapillary Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-analysis of Disease Characteristics and Treatment Outcomes

Micropapillary Versus Urothelial Carcinoma of the Urinary Bladder: Stage at Presentation and Efficacy of Chemotherapy Across All Stages-A SEER-based Study

BACKGROUND

Stage-specific guideline recommendations are lacking for chemotherapy in micropapillary carcinoma of the urinary bladder (MCUB).

OBJECTIVE

To test the efficacy of stage-specific chemotherapy for MCUB.

DESIGN, SETTING, AND PARTICIPANTS

Within the Surveillance, Epidemiology and End Results (SEER) registry (2001-2016), we identified patients with MCUB and pure urothelial carcinoma of the urinary bladder (UCUB) of all stages.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier survival analyses and multivariate Cox regression models were used to determine cancer-specific mortality (CSM) in addition to power analyses.

RESULTS AND LIMITATIONS

Of 210 491 patients of all stages, 518 (0.2%) harboured MCUB versus 209 973 (99.8%) UCUB. Stage at presentation was invariably higher in MCUB than in UCUB patients. Of the MCUB patients, 223 (43.1%) received chemotherapy versus 42 921 (20.4%) of the UCUB patients. In MCUB patients, chemotherapy improved CSM-free survival significantly in metastatic stage (hazard ratio [HR] 0.36, p = 0.04). Longer median CSM-free survival was also associated with chemotherapy use in addition to radical cystectomy (RC) versus RC alone in non-organ-confined MCUB (HR 0.69, p = 0.2). Additional power analyses revealed an underpowered comparison. Finally, no CSM difference was recorded in organ-confined MCUB according to the use of chemotherapy in addition to RC versus RC alone (HR 0.98, p = 1).

CONCLUSIONS

Stage at presentation was invariably higher in MCUB than in UCUB patients. Very important CSM reduction was associated with chemotherapy use in metastatic MCUB. A promising protective effect of perioperative chemotherapy might also be applicable to non-organ-confined MCUB, but without sufficient statistical power. Conversely, no association was recorded in organ-confined MCUB.

PATIENT SUMMARY

Patients with micropapillary carcinoma of the urinary bladder (MCUB) present in higher tumour stages than those with urothelial carcinoma of the urinary bladder. Chemotherapy for MCUB is effective in metastatic stages, but of no beneficial effect in organ-confined stage. In not-yet-metastatic but already non-organ-confined stages, we did not have enough observations to show a statistically significant protective effect of chemotherapy.

Pathological and Survival Outcomes Associated with Variant Histology Bladder Cancers Managed by Cystectomy with or without Neoadjuvant Chemotherapy

PURPOSE

Although neoadjuvant chemotherapy is associated with a survival advantage in pure urothelial, muscle invasive bladder cancer, the role of neoadjuvant chemotherapy is less clear in variant histology or urothelial carcinoma with divergent differentiation. We compared chemotherapy response and survival outcomes of patients with nonpure urothelial carcinoma histology who were managed with neoadjuvant chemotherapy followed by cystectomy vs cystectomy alone.

MATERIALS AND METHODS

We analyzed 768 patients with clinical muscle invasive bladder cancer (cT2-4N0M0) who were treated with cystectomy at a tertiary care center from 2007 to 2017. Patients were stratified by histology and treatment strategy. Adjusted logistic and Cox regression models were used to evaluate pathological downstaging, cancer specific survival and overall survival.

RESULTS

The cohort consisted of 410 patients (53%) with pure urothelial carcinoma, 185 (24%) with urothelial carcinoma with divergent differentiation and 173 (23%) with variant histology. Overall, 314 patients (41%) received neoadjuvant chemotherapy prior to cystectomy. There were similar rates of complete (18% to 30%) and partial (37% to 46%) pathological downstaging with neoadjuvant chemotherapy across all histological subgroups (p=0.30 and p=0.40, respectively). However, while patients with pure urothelial carcinoma experienced an overall survival benefit (HR 0.71, 95% CI 0.51-0.98, p=0.0013) and those with variant histology experienced a cancer specific survival benefit (HR 0.55, 95% CI 0.30-0.99, p=0.0495) with neoadjuvant chemotherapy, patients with urothelial carcinoma with divergent differentiation did not experience overall or cancer specific survival benefits with the use of neoadjuvant chemotherapy prior to cystectomy.

CONCLUSIONS

Among patients with muscle invasive bladder cancer those with nonpure urothelial carcinoma histology with variant histology achieved nearly equivalent response rates and survival benefits with the use of neoadjuvant chemotherapy as those with pure urothelial carcinoma, while patients with urothelial carcinoma with divergent differentiation experienced significantly worse survival outcomes regardless of the use of neoadjuvant chemotherapy prior to cystectomy.

Neoadjuvant therapy for muscle-invasive bladder cancer

INTRODUCTION

Muscle-invasive bladder cancer (MIBC) is generally a highly aggressive malignancy with early and mostly distant recurrences. Cisplatin-based combinations have been established as neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) providing overall survival as well as disease-free survival benefit. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic urothelial carcinoma and are being tested in the neoadjuvant setting as well.

AREAS COVERED

This review covers the existing guidelines for the management of MIBC. It summarizes the use of different NAC regimens. It also discusses the published literature of ICIs in this setting and explores future perspectives.

EXPERT OPINION

Cisplatin-based NAC is the standard of care in MIBC prior to RC. Cisplatin-ineligible MIBC patients have not demonstrated to clearly benefit from a chemotherapy regimen and proceed directly to RC, although novel agents have been evaluated in this setting. Pembrolizumab and atezolizumab as monotherapy have shown feasibility and promising pathologic response rates. The combination of cisplatin-based chemotherapy with ICIs and chemotherapy-free ICI alone approaches are being investigated in randomized trials. Molecular subclassification and development of predictive biomarkers in MIBC will further help to identify optimal treatment strategies in these patients.

Prognostic values of the clinicopathological characteristics and survival outcomes in micropapillary urothelial carcinoma of the bladder: A SEER database analysis

Purpose

To study prognostic values of the clinicopathological characteristics and survival outcomes in micropapillary urothelial carcinoma (MPUC) of the urinary bladder.

Method

We used the national Surveillance, Epidemiology, and End Results database (2004‐2016) to compare MPUC with transitional cell carcinoma (TCC) and to investigate prognostic values of clinicopathological characteristics, as well as survival outcomes, in MPUC of the urinary bladder. A multivariable Cox proportional hazard model, subgroup analyses, and propensity score matching were used.

Results

In all, 519 patients with MPUC and 154 453 patients with TCC were enrolled. Compared with TCC, patients with MPUC had a higher rate of muscle invasive disease (P < .001), lymph node metastasis (P < .001), and distal metastasis (P < .001), as well as higher tumor grade (P < .001). According to the survival analyses, the MPUC group also had lower survival probability in both cancer‐specific mortality (CSM) (P < .0001) and overall mortality (OM) analyses (P < .0001). Cox proportional hazard regression showed that the MPUC group had a higher risk of OM (hazard ratios [HR] = 1.39, 95% confidence intervals [CI] = 1.22‐1.57, P < .0001), although the CSM (HR = 1.18, 95% CI = 1.00‐1.40, P = .0505) in that group was fair. In the subgroup analysis, only MPUC patients without distal metastasis faced a higher risk of CSM (HR = 1.33, 95% CI = 1.101.61, P < .0001).

Conclusions

Micropapillary urothelial carcinoma prognosis is poorer than that of TCC. Micropapillary urothelial carcinoma is an independent prognostic factor for OM in patients with urinary bladder cancer.

Safety and Short-Term Oncological Outcomes of Thulium Fiber Laser En Bloc Resection of Non-Muscle-Invasive Bladder Cancer: A Prospective Non-Randomized Phase II Trial

BACKGROUND: Ongoing efforts aim at overcoming the challenges of conventional transurethral resection of bladder tumor (TURBT) such as the high recurrence rate, difficulty of pathologic interpretation and complications including wall injury. OBJECTIVE: To prospectively assess the safety and efficacy of Thulium fiber en bloc resection of bladder tumor (Tm-fiber ERBT) compared to TURBT. MATERIALS AND METHODS: The prospective non-randomized study included 129 patients with non-muscle-invasive bladder cancer (NMIBC) divided into two groups: 58 patients underwent conventional TURBT and 71 –Tm-fiber ERBT with FiberLase U1 (NTO IRE-Polus, Russia). Relapse-free survival (RFS), detrusor presence and complication rates were assessed. For multivariable analysis we used the Pearson chi-squared Hosmer-Lemeshow goodness of fit test; to compare survival –Cox regression analysis; for operative data comparison –chi-square test with Fisher’s correction; for survival analysis –the Kaplan–Meier method and logrank test. RESULTS: RFS rates at 3 and 6 months were 84.5% and 67.2% for conventional TURBT versus 97.2% and 91.5% for Tm-fiber ERBT (p = 0.011 and p < 0.001, respectively). Detrusor muscle was present in 58.6% of cases treated with conventional TURBT vs 91.6% for the Tm-fiber ERBT group (p < 0.001). The obturator nerve reflex and bleeding were noted in 17.2% and 10.3% of TURBT cases, respectively; and in none of cases treated with Tm-fiber ERBT. Limitations included the non–randomized nature and the small sample size. CONCLUSIONS: Tm-fiber ERBT seems to be a safe and efficacious treatment option for NMIBC. Tm-fiber ERBT had fewer adverse events, was more likely to secure detrusor muscle in the specimen and resulted in better RFS rates than conventional TURBT. Based on these promising data, we have started a prospective randomized clinical trial comparing en bloc TURBT with conventional TURBT (ClinicalTrials.gov NCT03718754).

Clinically node-positive micropapillary bladder cancer in a young female desiring to spare functional bladder and fertility

A 38-year-old female developing pelvic lymph node recurrence (cN2) of bladder cancer was referred to our hospital. Eighteen months earlier, she had received complete transurethral resection of bladder tumor and pathological diagnosis of muscle-invasive urothelial carcinoma with micropapillary variant had been made. She had declined radical cystectomy or chemoradiation because of a strong desire to spare the bladder and fertility. She received induction gemcitabine/cisplatin therapy. After three cycles, she achieved a clinically complete response. Then, she underwent transumbilical gasless retroperitoneoscopic super-extended pelvic lymph node dissection up to the inferior mesenteric artery trunk using the three-dimensional head-mounted display system. Pathologically, one of 42 resected lymph nodes was positive for metastasis. She is alive with no evidence of disease 5 years after lymph node dissection, retaining functional bladder and normal ovarian functions.

The role of device-assisted therapies in the management of non-muscle invasive bladder cancer: A systematic review

OBJECTIVE

Despite optimal treatment, patients affected by non-muscle invasive bladder cancer (NMIBC) suffer from high risk of recurrence and progression. Intravescical device assisted therapies such as radiofrequency induced thermochemotherapeutic effect (RITE) and electromotive drug administration (EMDA) have shown promising effect in enhancing the effect of intravescical chemotherapies. The aim of the study was to assess clinical outcomes of these two devices in non-muscle invasive bladder cancer.

METHODS

A systematic literature review was performed in December 2019 using the Medline, Embase, and Web of Science databases. Only articles published in the last 10 years were considered (2009-2019). The articles were selected using the following keywords association: "bladder cancer" AND "EMDA' AND "synergo" AND "hyperchemotherapy" AND "electromotive drug administration", AND "radiofrequency induced thermochemotherapeutic" AND "RITE".

RESULTS

We found 16 studies published in the last ten years regarding the efficacy of RITE (12 studies) and EMDA (4 studies) in the treatment of NMIBC. Both RITE and EMDA showed promising results in the treatment of intermediate and high risk NMIBC as well as in patients affected by recurrent BCa after BCG failure. In high-risk BCG naïve NMIBC patients treated with EMDA recurrence and progression rates were 68% and 95%, respectively. Considering RITE, recurrence and progression range rates were 43%-88% and 62%-97%, respectively. Discordance results were reported regarding its effect on patients with carcinoma in situ. However, only few studies could be compared since differences exist regarding inclusion criteria with high patients' heterogeneity. Considering recurrence after BCG, recurrence and progression range rates were 29%-29.2% and 62%-83% for RITE and 25% and 75% for EMDA, respectively.

CONCLUSION

Delivery of intravescical hyperthermia seems to enhance the normal effect of intravescical chemotherapy instillation. Although prospective trials supported its effect on both BCG naïve and BCG failure patients, data are urgently required to validate these findings and to understand its effect on patients with carcinoma in situ.

LEVEL OF PROOF

3.

The prognostic value of the urokinase-plasminogen activator system (uPA) in bladder cancer patients treated with radical cystectomy (RC)

PURPOSE

Urokinase-plasminogen activator (uPA), its receptor (uPAR), and the plasmin-activator inhibitor type 1 (PAI-1) have been associated with oncologic outcomes in various malignancies and could help identify bladder cancer (BC) patients treated with radical cystectomy (RC) who are likely to benefit from intensification of therapy to prevent disease progression. Our aim was to assess the value of uPA, uPAR, and PAI-1 for prognosticating survival outcomes of patients treated with RC for BC.

MATERIALS AND METHODS

Tumor specimens from 272 consecutive patients treated with RC for advanced BC were assessed with immunohistochemical staining for uPA, uPAR, and PAI-1. Overexpression was assessed by pathological image analysis. Kaplan-Meier estimates and multivariable Cox-regression were used to analyze survival. Harrell's C-index was used to assess for clinical impact of the uPA system.

RESULTS

uPA, uPAR, and PAI-1 were overexpressed in 48.2%, 51.1%, and 52.2% of patients, respectively. uPA overexpression was associated with lymphovascular invasion (P = 0.034) and nodal status (P = 0.013); PAI-1 overexpression was associated with primary muscle-invasive BC (P = 0.015) and lymphovascular invasion (P = 0.024). uPA, uPAR, and the number of overexpressed markers were all 3 significantly associated with shorter overall recurrence-free-, distant recurrence-free-, and cancer-specific survival. In multivariable analyses, uPA overexpression remained associated with shorter recurrence-free survival (hazard ratio [HR] = 1.79; P = 0.036) in the entire cohort, in patients without lymph node metastasis (HR = 1.98; P = 0.018) and those with nonorgan-confined disease (HR = 1.98; P = 0.022). uPAR overexpression was associated with shorter recurrence-free survival in patients without lymph node metastasis (HR = 2.01; P = 0.021) and those with organ-confined disease (HR = 4.11; P = 0.037).

CONCLUSION

Members of the uPA system are associated with features of biologically aggressive BC and oncologic outcomes. However, their value beyond currently available information remains limited.

Micropapillary urothelial carcinoma of urinary bladder displays immunophenotypic features of luminal and p53-like subtypes and is not a variant of adenocarcinoma

OBJECTIVES

Micropapillary urothelial carcinoma of the urinary bladder (MPUC) is a rare variant of urothelial carcinoma which has aggressive clinical characteristics. The objective is to investigate the molecular subtypes of MPUC and the impact to the clinical outcome and determine whether MPUC represents a variant of adenocarcinoma.

MATERIALS AND METHODS

We evaluated surrogate immunohistochemical markers of luminal, basal, and p53-like subtypes and correlated with prognosis and the expression of markers related to bladder adenocarcinoma and glandular differentiation in 56 cases of MPUC (10 cases of transurethral resection and 46 cases of radical cystectomy). Biomarker expression in co-existing conventional urothelial carcinoma was also analyzed. Cox regression analysis was performed to study the impact of molecular subtype on the clinical outcome.

RESULTS

Thirty-four cases (61%) met criteria for the luminal subtype. Twenty-two cases (39%) displayed a p53-like subtype. In contrast, 40/56 (71%) cases of coexisting conventional urothelial carcinoma were classified as luminal subtype and 16/56 (29%) cases were designated as p53-like subtype. There was no significant survival difference between luminal subtype and p53-like subtype. CDX2, villin, and cadherin 17 were negative in all cases. MUC1 was strongly and diffusely expressed in the stroma-facing surface of MPUC tumor cells in all the cases.

CONCLUSIONS

Our findings suggest that MPUC possesses characteristics of luminal and p53-like subtypes, and does not harbor phenotypic features of the basal subtype. There is no significant difference in the prognosis between luminal and p53-like subtype MPUC. MPUC is not a variant of adenocarcinoma and does not represent a form of glandular differentiation, in contrast to other organ sites.

Comparative Effectiveness of Intravesical BCG-Tice and BCG-Moreau in Patients With Non-muscle-invasive Bladder Cancer

BACKGROUND

The purpose of this study was to compare the efficacy of 2 bacillus Calmette-Guérin (BCG) strains, BCG-Tice and BCG-Moreau, in the treatment of non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We retrospectively reviewed clinical data from patients treated with BCG for NMIBC at 3 academic centers. Inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier curves and Cox proportional hazards regression analyses were used to compare recurrence-free (RFS) and progression-free survival (PFS) of patients in the 2 treatment groups. In addition, we performed exploratory analyses of treatment effect according to the receipt of adequate BCG treatment, high-risk disease, age, gender, smoking status, pathologic stage, and pathologic grade.

RESULTS

A total of 321 (48.6%) patients were treated with BCG-Tice and 339 (51.4%) with BCG-Moreau. IPTW-adjusted Cox proportional hazard regression analysis did not show a difference in RFS (hazard ratio, 0.88; 95% confidence interval, 0.56-1.38; P = .58) or PFS (hazard ratio, 0.55; 95% confidence interval, 0.25-1.21, P = .14) between BCG-Tice and BCG-Moreau. On subgroup analyses, we could not identify an association of BCG strain with outcomes.

CONCLUSIONS

There was no difference in RFS and PFS between BCG-Tice and BCG-Moreau strains in the adjuvant treatment of NMIBC. However, we confirmed the importance of maintenance therapy for achieving a sustainable response in patients with intermediate- and high-risk NMIBC.

Morphologic and genomic characterization of urothelial to sarcomatoid transition in muscle-invasive bladder cancer

INTRODUCTION

The sarcomatoid morphology of muscle-invasive bladder cancer (MIBC) is associated with unfavorable prognosis. However, the genomic, transcriptomic, and proteomic relationship between conventional urothelial and synchronous sarcomatoid morphology is poorly defined.

METHODS

We compiled a cohort of 21 MIBC patients with components of conventional urothelial and adjacent sarcomatoid morphology within the same tumor focus. We performed comprehensive pathologic and immunohistochemical characterization and in 4 selected cases, subjected both morphologic components to targeted DNA sequencing and whole transcriptome analysis.

RESULTS

Synchronous sarcomatoid and urothelial morphology from the same MIBC foci shared truncal somatic mutations, indicating a common ancestral clone. However, additional mutations or copy number alterations restricted to the either component suggested divergent evolution at the genomic level. This was confirmed at the transcriptome level since while the urothelial component exhibited a basal-like subtype (TCGA2014: cluster III, LundTax: basal/squamous-like), the sarcomatoid morphology was predominantly cluster IV (claudin-low). Protein expression was consistent with a basal-like phenotype in both morphologies in 18/21 of cases. However, most cases had evidence of active epithelial-to-mesenchymal transition (E-Cad ↓ and Zeb1 or TWIST1 ↑) from urothelial toward the sarcomatoid morphology. Drug response signatures nominated different targets for each morphology and proposed agents under clinical investigation in liposarcoma or other sarcoma. PD-L1 expression was higher in the sarcomatoid than the urothelial component.

CONCLUSIONS

Conventional urothelial and adjacent sarcomatoid morphologies of MIBC arise from the same common ancestor and share a basal-like phenotype. However, divergence between the morphologies at the genome, transcriptome, and proteome level suggests differential sensitivity to therapy.

Prognostic value of T1 substaging on oncological outcomes in patients with non-muscle-invasive bladder urothelial carcinoma: a systematic literature review and meta-analysis

Purpose

To evaluate the prognostic value of substaging on oncological outcomes in patients with T (or pT1) urothelial carcinoma of the bladder.

Methods

A literature search using PubMed, Scopus, Web of Science, and Cochrane Library was conducted on March 2019 to identify relevant studies according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. The pooled disease recurrence (DR) and disease progression (DP) rate in T1(or pT1) patients were calculated using a fixed or random effects model.

Results

Overall 36 studies published between 1994 and 2018 including a total of 6781 bladder cancer patients with T1(or pT1) stage were selected for the systematic review and meta-analysis. Twenty-nine studies reported significant association between tumor infiltration depth or muscularis mucosa (MM) invasion and oncological outcomes. Totally 12 studies were included in the meta-analysis. MM invasion (T1a/b/c [or pT1a/b/c] or T1a/b [or pT1a/b] substaging system) was associated with DR (pooled HR: 1.23, 95%CI: 1.01–1.49) and DP (pooled HR: 2.61, 95%CI: 1.61–4.23). Tumor infiltration depth (T1 m/e [or pT1 m/e] substaging system) was also associated with DR (pooled HR: 1.49, 95%CI: 1.11–2.00) and DP (pooled HR: 3.29, 95%CI: 2.39–4.51).

Conclusions

T1(or pT1) substaging in patients with bladder cancer is of prognostic value as it is associated with oncologic outcomes. Inclusion of this factors into the clinical decision-making process of this heterogeneous tumor may improve outcomes, while avoiding over- and under-treatment for T1(or pT1) bladder cancer.

How to Treat a Patient with T1 High-grade Disease and No Tumour on Repeat Transurethral Resection of the Bladder?

A relatively young (64-yr old) long-term heavy smoker but otherwise very healthy man is diagnosed with a primary unifocal left-side tumour (urothelial, T1 high grade), but no lymphovascular invasion and no variant histology. We discuss whether treatment with intravesical bacillus Calmette-Guérin vaccine will be sufficient or early radical cystectomy is at least equally preferred regarding patient benefit, safety, and quality of life. PATIENT SUMMARY: A patient with a single high-grade T1 bladder tumour without aggressive features (eg, lymphovascular invasion or variant tumour aspects) will be adequately treated with bacillus Calmette-Guérin intravesical therapy delivered into the bladder, followed by 3 yr of maintenance. However, all decisions should be taken with the patient in a shared decision-making process, including a discussion regarding removal of the bladder.

Morphologic and genomic characterization of urothelial to sarcomatoid transition in muscle-invasive bladder cancer

INTRODUCTION

The sarcomatoid morphology of muscle-invasive bladder cancer (MIBC) is associated with unfavorable prognosis. However, the genomic, transcriptomic, and proteomic relationship between conventional urothelial and synchronous sarcomatoid morphology is poorly defined.

METHODS

We compiled a cohort of 21 MIBC patients with components of conventional urothelial and adjacent sarcomatoid morphology within the same tumor focus. We performed comprehensive pathologic and immunohistochemical characterization and in 4 selected cases, subjected both morphologic components to targeted DNA sequencing and whole transcriptome analysis.

RESULTS

Synchronous sarcomatoid and urothelial morphology from the same MIBC foci shared truncal somatic mutations, indicating a common ancestral clone. However, additional mutations or copy number alterations restricted to the either component suggested divergent evolution at the genomic level. This was confirmed at the transcriptome level since while the urothelial component exhibited a basal-like subtype (TCGA2014: cluster III, LundTax: basal/squamous-like), the sarcomatoid morphology was predominantly cluster IV (claudin-low). Protein expression was consistent with a basal-like phenotype in both morphologies in 18/21 of cases. However, most cases had evidence of active epithelial-to-mesenchymal transition (E-Cad ↓ and Zeb1 or TWIST1 ↑) from urothelial toward the sarcomatoid morphology. Drug response signatures nominated different targets for each morphology and proposed agents under clinical investigation in liposarcoma or other sarcoma. PD-L1 expression was higher in the sarcomatoid than the urothelial component.

CONCLUSIONS

Conventional urothelial and adjacent sarcomatoid morphologies of MIBC arise from the same common ancestor and share a basal-like phenotype. However, divergence between the morphologies at the genome, transcriptome, and proteome level suggests differential sensitivity to therapy.

Histological variants in non-muscle invasive bladder cancer

Several studies evaluated the role of histological variants on oncological outcomes after radical cystectomy (RC) and they were found significantly associated with worse recurrence and survival. Sparse data exists regarding the role variant histology in non-muscle invasive diseases: assessing their relationship with recurrence and progression is important to understand the most effective treatment and follow-up schedule. For these reasons, the aim of the present non-systematic review was to assess the literature on variant histology in non-muscle invasive bladder cancer (BCa). The diagnosis of presence variant histology at transurethral resection (TUR) specimens challenging for pathologists and several studies published in literature evaluated concordance between TUR and RC specimen with discordant results. These differences are probably related to diversity in collection of samples and pathological evaluation and underline the necessity to have good tissue-sample and a pathologic evaluation performed by expert and dedicated uropathologists. Treatment of BCa with variant histology shall include immediate RC in case of plasmacitoid, pure squamous, micropapillary and sarcomatoid variants. The neuroendocrine differentiation, therefore, showed chemosensitiveness, and RC preceded by neoadjuvant chemotherapy should be proposed. Intravesical instillations with Bacillus Calmette Guerin (BCG) can be suggested in very selected cases of nested and glandular variants.

Molecular Predictors of Complete Response Following Neoadjuvant Chemotherapy in Urothelial Carcinoma of the Bladder and Upper Tracts

Urothelial carcinoma of the bladder (UCB) and upper tracts (UTUC) is often regarded as one entity and is managed generally with similar principles. While neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is an established standard of care in UCB, strong evidence for a similar approach is lacking in UTUC. The longest survival is seen in patients with complete response (pT0) on pathological examination of the RC specimen, but impact of delayed RC in nonresponders may be detrimental. The rate of pT0 following NAC in UTUC is considerably lower than that in UCB due to differences in access and instrumentation. Molecular markers have been evaluated to try to predict response to chemotherapy to reduce unnecessary treatment and expedite different treatment for nonresponders. A variety of potential biomarkers have been evaluated to predict response to cisplatin based chemotherapy including DNA repair genes (ATM, RB1, FANCC, ERCC2, BRCA1, and ERCC1), regulators of apoptosis (survivin, Bcl-xL, and emmprin), receptor tyrosine kinases (EGFR and erbB2), genes involved in cellular efflux (MDR1 and CTR1), in addition to molecular subtypes (Basal, luminal, and p53-like). The current state of the literature on the prediction of response to NAC based on the presence of these biomarkers is discussed in this review.